VDSL deployment suffers from various types of interference, noise, etc. These typically have included self-FEXT (i.e., far-end crosstalk generated from within a given domain or group of lines), alien FEXT (from one or more alien noise sources outside the domain), impulse noise, and radio frequency interference (RFI). Self-FEXT has been the dominant problem in such deployments. Using MIMO VDSL vectoring, self-FEXT can be cancelled very effectively. Such self-FEXT cancellation changes the VDSL noise environment substantially, for example by permitting alien noise from outside the system to become more apparent and/or significant. That is, in a generally self-FEXT-free environment, alien noise (e.g., alien FEXT, impulse noise, RFI, etc.) typically become the dominant disturbances limiting system performance. Much of this type of alien noise is from a single source, couples to all lines in a bundle in a similar fashion, and is correlated.